<!DOCTYPE html>
<html>

<head>
    <style>
        * {
            box-sizing: border-box;

        }

        body {
            font-size: 16px;
            font-family: Arial, Helvetica, sans-serif;
        }

        main {
            width: 80%;
            /* height: 300px; */
            box-shadow: 0 5px 8px gray;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            border-top: 5px solid #008b8b;
            border-radius: 5px;
            /* text-align: center; */
            padding: 2rem 1.5rem 1.5rem 3rem;
        }

        div {
            text-align: center;
        }

        h1 {
            color: #008b8b;
        }

        form div {
            margin-bottom: 1rem;
            text-align: left;
            /* display: table-cell;
            vertical-align: middle; */

        }

        input,
        select,
        textarea {
            border: none;
            padding: 0.75rem 1rem;
            background-color: whitesmoke;
            border-radius: 0.25rem;
            font-size: 1rem;
            width: 100%;
            resize: vertical;
            border: 1px solid transparent;
        }

        label {
            margin-bottom: .5rem;
            display: inline-block;
        }

        #user-name {
            background-image: url(./头像.png);
            background-size: 2rem;
            background-repeat: no-repeat;
            background-position: 3px center;
            padding: 0.75rem 3rem;
        }

        input:focus,
        select:focus,
        textarea:focus {
            /* padding: calc(0.75rem + 1px) calc(1rem + 1px); */
            background-color: #fff;
            border: 1px solid #008b8b;
            box-shadow: 0px 2px 2px #008b8b;
            outline: none;
        }

        input[type="submit"] {
            width: auto;
            padding: 12px 20px;
            background-color: #008b8b;
            color: white;
            border: none;
            border-radius: 4px;
            float: right;
        }



        @media screen and (min-width: 600px) {
            form div {
                text-align: right;
            }


            input,
            select,
            textarea {
                margin-left: 0;
                width: calc(100% - 110px);
                vertical-align: middle;
            }

            /* label[for="suggestion"] {
                position: relative;
                bottom: 2.5rem;
            } */
            #suggestion {
                vertical-align: top;
            }
        }
    </style>
</head>

<body>
    <main>
        <div>
            <h1>Register</h1>
        </div>

        <form>
            <div>
                <label for="full-name">Full Name</label>
                <input type="text" placeholder="Your full name..." id="full-name">
            </div>

            <div>
                <label for="user-name">User Name</label>
                <input type="text" placeholder="User Name" id="user-name">
            </div>

            <div>
                <label for="password">Password</label>
                <input type="password" placeholder="Your password..." id="password">
            </div>

            <div>
                <label for="address">Address</label>
                <select id="address">
                    <option>China</option>
                    <option>USA</option>
                    <option>Japan</option>
                </select>
            </div>

            <div>
                <label for="suggestion">Suggestion</label>
                <textarea id="suggestion" placeholder="Write something..."></textarea>
            </div>

            <div>
                <input type="submit" value="submit">
            </div>


        </form>
    </main>
</body>

</html>